Acoustic measuring devices have been used for determining a level or height of a fluid surface in a fluid container. A sound transducer of the acoustic measuring device can operate both as sound generator and as sound receiver. For the purposes of determining the height of the fluid surface in the fluid container, it is possible to emit sound pulses into the fluid to be measured by means of the sound transducer. The sound pulses are reflected by an interface of the fluid to a further medium. From the time-of-flight of the sound pulses, it is possible to draw conclusions about the height of the fluid surface in the fluid container.